The association between inflammatory markers (iNOS, HO-1, IL-33, MIP-1β) and depression with and without...

Both major depression and posttraumatic stress disorder (PTSD) are characterized by inflammation, increased concentration levels of proinflammatory cytokines, decreased neurogenesis followed by neuroprogression, as well as mitochondrial and the hypothalamic-pituitary-adrenal axis dysfunction. Elevated levels of oxidative stress caused by an increased activity of prooxidants over antioxidants are also observed. Based on several reports, depressive episodes can lead to the sensitization of immune-inflammatory pathways. Thus, depression, PTSD, and depression comorbid with PTSD are associated with immune-inflammatory markers. The study aimed at evaluating concentration levels of iNOS, HO-1, IL-33, and MIP-1β in depression with and without PTSD.

A total number of participants enrolled in the study was 460. Out of them, 420 subjects with various levels of depression severity constituted the study group (210 males and 210 females), and 40 subjects (20 males and 20 females) constituted the control group. Each study group comprised 60 patients (30 males and 30 females) with mild depression (MD), moderate depression (MOD), severe depression (SeD), MD and PTSD (MD+PTSD), MOD and PTSD (MOD+PTSD), SeD and PTSD (SeD+PTSD), and with PTSD alone. At 7:00 a.m., all patients had serum concentrations of iNOS, HO-1, IL-33, MIP-1β determined using ELISA.

Both depression exacerbation and PTSD comorbidity led to elevated levels of iNOS, HO-1, IL-33, and MIP-1β.

Depression both with and without PTSD leads to elevated levels of inflammation and an oxidant/antioxidant imbalance. Alterations in both cytokines and oxidative stress are related to the mechanisms responsible for the development of depressive symptoms.